And to be clear, it does run at 12 volts as well. However, the controller will turn the HV off at around 110-130 milliamps as the inductor duty cycle approaches 100%.
On Saturday, September 21, 2019 at 10:07:07 PM UTC-4, Kevin A. wrote: > > Update: > > A quick test shows that the 40 watt version works! It turns out, however, > that 12 volts in is a bit too low for this design at this power level. By > upping the input voltage to 24 volts (which is reasonable - there are > plenty of cheap 24 volt wall warts as well), the design functioned as > intended (all components within rated spec at 24 volts as well). Output > across a fixed 876 ohm load settled at 179 volt ~201 milliamps for a 24 > volt 1.65 amp input, which translates to 91% efficiency. There really isn't > any practical benefit to running at 12 volts with double the input current. > Efficiency would drop and heat would increase throughout the circuit to > attain the same power. > > If any clocks or systems out there need a lower operating voltage and you > want to run off of one power input, I can add 24 volt breakouts for your > own DC-DC converter. A second option would be to build in a second switcher > to step the input 24 volts down to an adjustable voltage between 1.2V-24V. > This is fairly straightforward using a controller like the LM2576T-ADJ. It > will, however, increase size and cost (current size is 3.3 inches x 2.1 > inches). > > I want to perform some thermal testing when I have access to my infrared > camera this week as well. I did some poking around to see what was warm > after the supply was turned off. As expected, the transistor and diode did > produce some heat, but they were only warm to touch. My 100 watt load > resistor, however, was getting pretty warm! > -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To unsubscribe from this group and stop receiving emails from it, send an email to neonixie-l+unsubscr...@googlegroups.com. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/05033a3c-4ab9-4837-9dac-62c5bc9de3ab%40googlegroups.com.
